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The Genesis of the Kramer Borax Deposit, Rogers Lake, Mojave Desert, CA: A 50 Year Retrospective
by Carl Bowser
Abst: Borax serves a broad spectrum of industrial uses ranging from glazes, detergents, borosilicate glasses, fire suppressants, and agricultural medical products. Its history and use goes back several millennia, yet it wasn’t until the year 1294 that borax became known to the “Western World” through the travels of Marco Polo. Chemically boron has charge/radius properties allowing it to exist in three and four fold coordination with oxygen allowing it to substitute in silicon and aluminum coordinated minerals. Boron bearing minerals are numerous and form over a large range of geologic conditions.
Industrial boron is largely derived from sedimentary, non-marine evaporite deposits that are primarily Tertiary age or younger. In the US boron producing localities are generally restricted to the Cordilleran basin and range province, including Death Valley, Searles Lake, and Borax Lake. Significant other deposits are found in South America, Turkey, Italy, and Tibet. Deposits in Death Valley have been exploited since 1882, but these ulexite and colemanite dominated deposits were costlier to process than pure borax. The Kramer borax deposit was discovered in 1925, and its size and purity led to its being the primary source of boron for most of the world through the late 20th century. In more recent years significant deposits in Turkey and South America (Peru, Chile, Bolivia) have overtaken the world market, with Turkey’s deposits being the principal source in recent years.
A comparison of non-marine deposits in Turkey and South America reveal nearly identical patterns of deposition, mineralogy, and links to geothermal systems. Argued to have formed in shallow, meromyctic lakes the borax textures and depositional sequence require sub-aqueous deposition in the absence of other typical evaporite minerals, putting severe restrictions on the range of compositions of the evaporating fluids. The deposits are characterized by being chemically zoned, as nested envelopes of sodium, sodium-calcium and calcium borates. Invariably a core of pure borax sediments are surrounded both laterally and vertically by a sodium-calcium borate facies, principally ulexite, and an outer envelope containing inyoite, meyerhofferite, and colemanite, the calcium borate facies.
Post depositional thermal alteration has generated a number of secondary borates in veins cross-cutting the ores and replacing earlier-formed, primary phases. Silicate and borate diagenesis in volcanic tuffs and claystones within the deposits are common. Development of Kernite and the existence of hydrothermal sulfide minerals such as realgar, orpiment, and stibnite belie links of the borate deposits to nearby thermal springs. More recent work using boron isotopic systems shed light on these processes, but the use of these and other isotopic systems has yet to be fully exploited.
The talk will focus on the Kramer deposit, but comparisons among major deposits in South American and Turkey will serve to highlight the common processes that formed these deposits, and some of the remaining questions on the origin of these unusual deposits.
Bio: Carl was born and raised in the Los Angeles area, a third generation native Californian. He got his undergraduate degree in geology at UC Riverside, 1959, and his Ph.D. in geology/geochemistry at UCLA in 1964 under the tutelage of F.W. Dickson and George Tunell. He accepted a position in the Geology Department at the University of Wisconsin, where he moved in January of 1964. His teaching career spanned nearly 37 years until his retirement in 2000. During his career he dedicated his research to interdisciplinary studies with colleagues in Water Chemistry, Soils, and Limnology and the Water Resources Division of the USGS. He chaired the Oceanography and Limnology Graduate program at UW for four years and was a lead principal investigator with the NSF-LTER project (Long Term Ecological Research) for the last 20 of his years at Wisconsin.
Broadly interested in mineral-water interaction and the geochemical controls on the chemistry of natural waters, his research work focused on non-marine evaporites, fresh water and marine ferromanganese nodules, the mineralogy of lake sediments, and studies of lake-groundwater systems using stable isotope and major ion systems. Research has taken him over the world including: Antarctica (two field seasons), dry lakes in the basin and range province including the Kramer borax deposit, Columbus and Teels Marsh, NV, the Great Salt Lake,UT, the eastern Pacific manganese nodule belt, freshwater nodules in Green Bay and upper Wisconsin lakes, saline thermal brines in the Red Sea, taconite waste disposal into Lake Superior, and ephemeral, shallow playa lakes in the Jornada del Muerto area, NM.
Over his time at Wisconsin he worked extensively with UW colleagues at the Center for Limnology, and USGS colleagues in the Reston office, principally Blair Jones, Ted Callender, T.C. Winter (Denver), R. Marzolf, M.J. Baedecker, and Carol Kendall (Menlo Park). The USGS has literally been his second home. Two sabbaticals in the Denver and Boulder USGS offices led to work on the Colorado River flood experiment in 1996 (R.Marzolf), and lake groundwater interactions in the Cottonwood Lake area, NE (T.C. Winter). For the four years immediately following his retirement he continued to complete research publication in the geosciences, while at the same time renewing a love for an old friend, the camera.
He joined photographers at the Center for Photography at Madison (now PhotoMidwest) where he served ten years on the board of directors, and two years as president. Workshop participation, visiting artists and travel to the western states exposed him to a large group of talented photographers, including some of the leading photographers of our time. Travel to Santa Fe and Abiquiu, New Mexico, and Big Sur for workshops helped develop his photographic skills. He has exhibited extensively at shows and local establishments in the Madison area. His northern Wisconsin work was exhibited in a small gallery in Boulder Junction. Western landscapes, glacial lakes, and human interest photography dominate his work.